The Doctor, Jamie and Polly are sent to work in the gas mines whilst Ben struggles to regain control of his mind. Jamie escapes into an old shaft where the Macra are waiting.

The Doctor is captured by the Sea Devils and taken to their undersea base. There he tries to make peace with the creatures, but his efforts are thwarted by the Navy.

Peter O'Brien is an Australian actor, best known for appearing in Neighbours.

O'Brien was born at Murray Bridge, South Australia. He started off as a teacher at Mercedes College, a private Catholic College, inSpringfield, Adelaide.

In the 1980s,  O'Brien  ventured into acting scoring a role in Australian television drama series. He played a regular role in short-lived soap opera Starting Out (1983), and had a guest role in Carson's Law (1983) followed by a brief appearance in Prisoner in 1984. He appeared in the The Henderson Kids. He was later a regular original cast member of soap Neighbours which began in 1985. As Shane Ramsay, he became one of the serial's most popular cast members, continuing in the series until 1987. He later played a leading regular role in drama series The Flying Doctors from 1988 until 1991.

More recently, he starred in television series Queer as Folk, White Collar Blue, Hell Has Harbour Views and Gossip Girl.

O'Brien has appeared in numerous mini-series, including The Day of the Roses and Through My Eyes (the story of Lindy Chamberlain). He has also guest starred on numerous television series, including Halifax f.p.. For his work, O'Brien has won Australian Film Instituteand Logie Awards. He also appeared as Carl Morgan in Spellbinder 2: Land of the Dragon Lord, and he appeared in the 1998 Australian/Brisbane comedy television series of Minty. In 2009 he played Sydney underworld figure and racing identity George Freemanin the series Underbelly: A Tale of Two Cities.^[1]

O'Brien was recently part of the cast of BBC Television series Casualty as a new consultant called Stitch. He made his debut on 18 March 2007. He has also appeared in ITV1s cop show The Bill in which he played Detective Inspector Peter Kavanaugh, a corrupt officer who seduces Detective Sergeant Samantha Nixon to gain information for the criminals he works for.

He appeared as Ed in "The Waters of Mars", the second of the 2009 specials of Doctor Who.

_{Biography from the Wikipedia article, licensed under CC-BY-SA}

Sir Elton Hercules John, CBE is an English rock singer-songwriter, composer, pianist and occasional actor. He has worked with lyricist Bernie Taupin as his songwriter partner since 1967; they have collaborated on more than 30 albums to date.

He appeared in a video clip on Elton Pope's video diary in the 2006 story Love and Monsters.

Susan Engel (born in Vienna, Austria) is a British actress.

She played Vivien Fay in the 1978 story The Stones of Blood.

Engel's work in theatre includes: Angels in America (1992), Richard III, King Lear (1990), The Good Person of Sezuan, Watch on the Rhine (1980), Spring Awakening, The Hour We Knew Nothing Of Each Other and Her Naked Skin (2008) at the National Theatre, London;Women Beware Women (2006), Luminosity (2001), Bad Weather, The Dybbuk, King John (1988), Cousin Vladimir (1978), The Tempest, The Comedy of Errors (1962), Julius Caesar (1963), Henry VI, Part 2 and The Wars of The Roses (1963) for the RSC;Spinning Into Butter, The Happy Haven, Hotel In Amsterdam (1968) and Macbeth at the Royal Court, London, Hecuba (2004) at theDonmar Warehouse, London; After The Gods, Ascent of Mt Fuji and Shortlist at the Hampstead Theatre, London; The Sea at theChichester Festival Theatre, Chichester; Prayers of Serkin at the Old Vic, London, A Passage to India (2003) for Shared Experience;Himself at the Nuffield Theatre, Southampton; Brand (2003), An Inspector Calls, The Clandestine Marriage (for which she won theClarence Derwent Award for Best Supporting Actress), Footfalls (1994), The Cherry Orchard, A Kind of Alaska (1985), Hamlet, The Last of the Red Hot Lovers and Three Sisters in the West End, London.

She remains best known for her work in television, including the series The Lotus Eaters. In 2003, she appeared in the popular detective series Midsomer Murders. Other TV credits include: afterlife, The Black Death, Quiet as a Nun, Dalziel and Pascoe, Trial and Retribution V, Thursday the 12th, The Vice, Kavanagh QC, Underworld and Inspector Morse andCrown Court. And, quite immensely popular at the time: The Cedar Tree

In 2004, she guest-starred in the audio drama Gallifrey: A Blind Eye, produced by Big Finish Productions. Other radio includes: Looking for Angels: Left at the Angel, The January Wedding, The Making of the English Landscape, The Great Pursuit, The Bruno Bettelheim Project, The Raj Quartet, Miss Esther's Guest, Are You Sure?, Peeling Figs for Julius, La Grande Therese, Anne of Green Gables and Black Narcissus.

Film credits include: The Magic Seed, The Leading Man, Damage, Ascendancy, Butley and King Lear

_{Biography from the Wikipedia article, licensed under CC-BY-SA}  

Patrick Troughton was born in Mill Hill, Middlesex, England to Alec George Troughton, a solicitor, and Dorothy Evelyn Offord. Troughton attended Mill Hill School and continued to live in Mill Hill for most of his life. While at Mill Hill School, he acted in a production of J.B. Priestley's "Bees on the Boat Deck" in March 1937.

He attended the Embassy School of Acting at Swiss Cottage, under Eileen Thorndike, and won a scholarship to the Leighton Rallius Studios at the John Drew Memorial Theatre on Long Island in New York, U.S.

In the Second World War he joined the Royal Navy and served as a Lieutenant, R.N.V.R. on East Coast Convoy duty from February to August 1941, and Coastal Forces (M.G.B.'s) based at Great Yarmouth from November 1942 to 1945, where he was mentioned in dispatches.

After the war, Troughton returned to the theatre working with the Amersham Repertory Company, the Bristol Old Vic Company and the Pilgrim Players at the Mercury Theatre, Notting Hill Gate. He made his television debut in 1947 and his fim debut a year later. In 1953 he became the first actor to play Robin Hood on television, starring in six half-hour episodes broadcast from 17 March to 21 April on the BBC. Troughton's other notable film and television roles included Kettle in Chance of a Lifetime (1950), Sir Andrew Ffoulkes in The Scarlet Pimpernel (1955), Phineas inJason and the Argonauts (1963), Quilp in The Old Curiosity Shop (1962), Paul of Tarsus (BBC 1960, title role), Dr. Finlay's Casebook (BBC 1962, semiregular). He voiced Winston Smith in a 1965 BBC Home Service radio adaptation of Nineteen Eighty-Four. Prior to Doctor Who he appeared in numerous TV shows including, The Count of Monte Cristo, Ivanhoe, Dial 999, Danger Man, Maigret, Compact, The Third Man, Crane, Detective, Sherlock Holmes, No Hiding Place, The Saint, Armchair Theatre, The Wednesday Play, Z-Cars, Adam Adamant Lives! and Softly, Softly.

In 1966, Doctor Who producer Innes Lloyd cast Troughton in the series, replacing {p1}}. Lloyd later stated that Hartnell had approved of the choice, saying, "There's only one man in England who can take over, and that's Patrick Troughton". Doctor Who creator Sydney Newman suggested he play the role as a "cosmic hobo" in the mould of Charlie Chaplin.

Producer Lloyd credited Troughton with a "leading actor's temperament. He was a father figure to the whole company and hence could embrace it and sweep it along with him". Troughton found Doctor Who's schedule gruelling, and decided to leave the series in 1969, after three years in the role. He later returned to the series on three separate occasions.

After Troughton left the series, he appeared in various films and television roles. Film roles included Klove in Scars of Dracula (1970), Father Brennan in The Omen (1976) and Melanthius in Sinbad and the Eye of the Tiger (1977). Television roles included the recurring role of Thomas Howard, 3rd Duke of Norfolk in five of the six episodes of The Six Wives of Henry VIII (1970), the villainous Nasca in Thames Television's Aztec-themed drama The Feathered Serpent (1976-1978), a guest starring spot in the comedy series The Goodies in the episode "The Baddies", as well as episodes of Paul Temple, Dr. Finlay Casebook, Doomwatch, The Persuaders!, A Family at War, Coronation Street, Softly, Softly: Taskforce, Colditz, Play for Today, Z-Cars, Special Branch, Sutherland's Law, The Sweeney, Jason King,Survivors, Crown Court, Angels, Warship, Van der Valk, Space: 1999, The Onedin Line, All Creatures Great and Small, Only When I Laugh (Series 2, Total Episode #9), Nanny, Minder, and the first episode ofInspector Morse. He portrayed Cole Hawlings in a BBC Television dramatisation of the John Masefield children's book The Box of Delights (1984).

Troughton's suffered two major heart attacks, one in 1978 and the other in 1984, which prevented him from working for several months. On Friday, 27 March 1987, Troughton was a guest at the Magnum Opus Con II science fictionC onvention in Columbus, Georgia, USA. He suffered a third and final heart attack at 7:25 a.m. the next day.

Troughton was married three times. He had two daughters and four sons, as well as a stepdaughter and stepson.

The actor is played by Reece Shearsmith in the 50th Anniversary drama An Adventure In Space And Time.